The oldest known example of a portable sundial is in the shape of a ham. The Ham of Herculaneum, which dates to the end of the 1st century, was discovered in 1755 in the Villa dei Papiri, a site destroyed in the eruption of Mount Vesuvius. The tiny bronze device shaped like a hunk of meat on a hook is one of the more curious survivors of the widespread culture of timekeeping in the Greek and Roman world.

Installation view of Time and Cosmos in Greco-Roman Antiquity at the Institute for the Study of the Ancient World, with the Ham of Herculaneum (photo by the author for Hyperallergic)

You could spend hours in the two-room Time and Cosmos learning how old sundials and calendars worked, ideas that are fleshed out in the accompanying catalogue. Many of these principles are still familiar thanks to their endurance in Christian Europe, such as the division of day and night into 12 hours each, something the Greeks adapted from the Egyptians. Meanwhile, the Roman calendar system that was instituted by Julius Caesar in 45 BCE informed the Gregorian calendar that’s still in use. Yet beyond the technical details — from shadows cast on carved lines to the complicated Antikythera mechanism (not on view but explored in video) — the exhibition excels at demonstrating the importance of time in everyday life.

“It became part of the everyday visual vocabulary,” curator Alexander Jones, who’s also a professor of history of the exact sciences in antiquity and interim director of the ISAW, explained at the preview. He pointed out a 140–160 CE marble frieze from a Roman sarcophagus with two putti (cherubs) attempting to interfere with a sundial, perhaps to reverse the chronology that has taken a life. Another wall features a display of coins from various eras, with astrological symbols like celestial spheres — which placed Earth at the center of the cosmos — used to indicate the emperor’s authority. And a Greek paragpegma calendar from 100 BCE aligns stellar phenomena with weather predictions; it is pocked with holes for pegs to mark the date.

Jones pointed out that every ancient civilization had some form of time management, but the Greeks and Romans were much more conscious of regulating it in both private and public life. The exhibition text states that more than 500 Greco-Roman sundials have been discovered, with 30 sundials at Pompeii alone.The oldest known Italian sundial, unearthed at Pompeii and dating to 100 BCE, is on view in Time and Cosmos, its conical shape delicately sculpted from marble. A 363–362 BCE stele that tracked both the date and cult activities shows another public system of timekeeping.

Then there were the water clocks and pre-wristwatch portable sundials owned by the elite. A case of objects from a 1st-century CE Roman physician’s tomb includes a cylindrical portable sundial made of deer bone, alongside forceps, scalp handles, and other medical instruments. Mass-produced calendar boards could be found in more common households. Time and Cosmos stresses how this ubiquity of timekeeping influenced everything in Greek and Roman life, down to people’s perceptions of self.

Ivory astrologer’s boards (photo by the author for Hyperallergic)

Among the most transfixing objects are two sets of rare zodiacal boards likely used by a traveling astrologer in the 2nd century CE. Made of ivory, wood, and gilding, the small boards were found in the 1960s at the bottom of a well in France, seemingly destroyed on purpose, perhaps because of their pagan imagery in the Late Antique era. The boards were used almost as maps of life, charted based on the exact day and hour at which a person was born. Just as the universe was believed to be impacted by the orientation of the moon and stars, so was a person’s body, along with its fortune and misfortunes. Near the boards are two papyri horoscopes written in Greek, both for the same man born early in the first hour of December 4, 137 CE, but made by different astrologers.

The cross between the spiritual and the scientific seen in Time and Cosmos reflects an ancient belief in how the heavens influenced human life on Earth. In the names of our months and the perception of our lives as marked by the passage of the hours, or guided by our zodiac signs, is a continuation of that understanding of the universe.